Implementation of optical CDMA based on passive optical networks

In this article, our aim is to investigate passive optical networking (PON) based fiber access systems. An overview of optical OCDMA and optical coding through their features such as increasing the capacity, security and improving the system performance were presented. Modified prime code, which represents a user address and signs each transmitted data bit has been chosen as a signature sequence code because of its good periodic auto/cross correlation properties. However, simulation and theoretically analysis of balanced detection scheme based on passive networking access taking into account the effects of various noises such as shot noise, phase-induced intensity noise (PIIN), thermal noises were presented as well. Results of 25 subscribers sent in C band for the upstream signal with channel spacing 25GHz show good system performance in terms of the bit error rate and suppressing the multiple access interference when variation of fiber length and data rate are applied.